Glottalized click
Glottalized clicks are click consonants pronounced with closure of the glottis. All click types have glottalized variants. They are very common: All of the Khoisan languages of Africa have them, as does Dahalo and the Bantu languages Yeyi and Xhosa. They are produced by making a glottal stop, which stops the flow of air, and then using the front of the tongue to make the click sound in the middle of the glottal stop.
Glottalized nasal clicks
In all languages which have them, glottalized clicks are nasalized, though a few have non-nasal glottalized clicks as well. Glottalized nasal clicks are formed by closing the glottis so that the click is pronounced in silence; however, the nasal passage is left open, and any preceding vowel will be nasalized. They are typically transcribed something like ' or ' or , and often !’ word-initially but n!’ between vowels. In Khoekhoe they are written with the single letters ǃ ǁ ǀ ǂ, in Juǀ’hõa, as ǃ’ ǁ’ ǀ’ ǂ’ with a preceding nasal vowel, in Sandawe as q’ x’ c’, in Hadza as qq xx cc, and in Xhosa as nkc nkx nkq.When full glottal closure is made, there is no nasal airflow during the click itself, and there is a period of silence after the click and before the pronunciation of the vowel. That is, they are pronounced, etc. In many languages, however, the glottal closure is not complete, in which case they are pronounced with accompanying voiceless nasal airflow and transcribed, etc. A more general transcription is ; superscripting the nasal and glottal components indicates that they are articulated simultaneously with the click and not adjacent to it.
Initially and in citation form, the nasal component may be inaudible. That is, in this position glottalized clicks differ from plain clicks in the gap between click and vowel, and from aspirated clicks in that this gap is silent rather than noisy. In canonical form, a glottal stop occurs between the release of the click and the start of the following vowel. In practice, though, the glottalization often 'leaks', with a creaky-voiced transition into the vowel. However, in medial position or embedded in a phrase after a vowel the nasalization can usually be heard: any preceding vowel will be nasalized or the click will be prenasalized. This is somewhat similar to aspirated nasal clicks, though in the later case the nasal airflow continues through the click itself. In neither case is the following vowel normally nasalized, something which occurs with simple nasal clicks in languages like Gǀui.